William hovey



UNITED STATES PATENT oEEIoE.

WILLIAM HOVEY, OF WORCESTER, MASSACHUSETTS.

MACHINERY FOR GrRIlI'DINGrV TOOLS.

Specification forming part of Letters Patent No. 4,204, dated September 23, A184:5; Reissued J une To all whom t may concern:

Be it known that I, WILLIAM HovEY, of t-he town and county of Vorcester and State of Massachusetts, have invented a new and` useful machine for grinding the twisted or spiralcutters or knives used in machines for cutting straw, and generally `known as Hoveys straw-cutter, and that the following is a full, clear, and exact description of the principle or character which distinguishes my invention from all other things before known and of the manner of making, constructing, and using the same, reference being had to the accompanying drawings, making part of this specification, in which- Figure 7 is a perspective representation of the machine, and Fig. 2, a transverse vertical section of the same.

The same letters are used in all the figures to indicate like parts.

The nat-ure of my invention consists in attaching the twisted, (sometimes called spiral) blades or` cutters, to a flanch proectinv from a stock hun on ournals in a traversing carriage, so as to present the back of the cutter to be ground to the action of a grindstone, or other reducing or polishing wheel, so that as the cutter on the carriage traverses lengthwise, it shall vibrate freely on the axis of the stock, to which it is attached, to follow the twist of the blade and grind it to a sharp edge, such as is required in cutting by impinging the cutting edges against the surface of a cylinder by the rotation of the two cylinders or the cutting cylinder on a plane the cutting being effected by a pressure toward the center of the axis of the cylinder of knives. The reciprocating motion of the cutters lduring the traverse motion being governed by the spiral or twisted surface of the knife itself, or any thing analogous thereto. v

In the accompanying drawings (A) rep resents the frame of the machine properly adapted to the operative parts.

(B) is the grinding wheel made of stone, or any other substance, mounted on a shaft (a) running in appropriate boxes (Z), b), and provided with a pulley to receive motion from any first mover. The spiral or twisted blades or cutters (c), (such as are used in my straw cutter), are attached by screws to a flanch on the stock or shaft (e), corresponding in form with the arms to which they are attached in my straw cutter, their plane radiating from the axis, or nearly so, and as before stated, they cut by pressure applied in the line of radii, or nearly so. This stock (e) is hung by center pins to the forward part of a carriage (f),

which traverses longitudinally and parallel with the axis of the grinding wheel (B), on Ways (g, g) on another carriage (71,), which slides on ways (i, z') on the frame (A), and

to the end piece of the carriage, and the other provided with a jointed catch link (n), so as to connect the carriage with the screw to traverse the cutter or knife when presented to the action of the grinder, and to disconnect it for the purpose of running back the carriage. Motion is given to the screw by a belt (o) from a small pulley on the shaft of the grinder to a large one (g) on the screw to reduce the motion.

Thespiral blade is kept up to the grinder, as it traverses, by means of a gage screw (r) that passes through an arm (s) attached to the under carriage (7L) and in front of the grindingsurface of the grinder, so as to insure the reduction of the edge of the spiral or twistedV knife to a line which when applied to the stock of the straw cutter will generate a cylinder. The motion of the under carriage (L), from, and toward the grinder, is effected by a screw (t), which has its bearing in a box (u) in the frame, and takes in a nut ('v) at the bottom of the carriage, and is provided with a crank handle, for the purpose of increasing or decreasing the Obliquity of the back to be ground, and to adapt it to the wear of the grinder. And the gage (r) is tapped into the arm (s), that it may be regulated to the position given to the knife by this carriage.

It will be obvious that instead of the movement of the under carriage (h), the same end may be attained by the bearings of the stock or shaft (e) being made to slide for adjustment in the upper carriage (f) or by making the Vspiral blades or knives with elongated holes for the fastening screws to pass through, that it may be drawn out from or approached to the shaft, either of which will eect the same end, viz, that of increasing or vdecreasing the inclination of the bevel to be ground, but the latter of these modifications will not adapt the machine to the grinding of blades intended for straw cutters of different sizes. It will be obvious also that instead of having the gage bear against the face of the knife or cutter, a spiral flanch may project from the stock or shaft and slide in a permanent jaw on the arm (s), or a projection from this arm may enter a spiral groove in the stock; in short any of the known mechanical equivalents may be substituted for the devices described and adopted by me to carry out my invention, viz: to .give to the stock, to which the knives or cutters are attached, a reciprocating motion on its aXis while it traverses longitudinally before the grinder, so as 'to give the required bevel to the ground face and a line to the cutting edge which in its rotation will generate a cylinder ;-and therefore,

Vhat I claim as my invent-ion and desire to secure by Letters Patent is,

Giving to t-he spiral or twisted knife or cut-ter, attached to a flanch in a line radiating (or nearly so) from the aXis of the stock, a traversing motion in the ydirection of its axis, in combination with a reciprocatng rotary motion on its aXis, when this latter motion is governed by the twisted plane of the cutter or anything essentially the same to enable the grinder to give the required bevel to the ground face and the proper line to the edge, substantially in the manner herein described.

i WILLIAM HOVEY.

Vitnesses CHAs. M. HOLLER, A. P. BROWNE.

.[FIRST PRINTED 1913.] 

